scholarly journals Stepwise regression and principal component analyses for quantitative traits of rapeseed genotypes at different sowing dates

2016 ◽  
Vol 61 (4) ◽  
pp. 323-332
Author(s):  
Valiollah Rameeh

The present research was done to assess the best selection criteria for yield improvement in rapeseed (Brassica napus L.) using stepwise regression and principal component analyses at different sowing dates. All the traits except 1000-seed weight were significantly affected by sowing dates. The results of stepwise regression analysis revealed that seeds per pod had an important role at the first and second sowing dates, but at the third and fourth sowing dates, pods per plant and days to flowering were more important than other yield components for a seed yield prediction model. On the basis of a cumulative percent of variation, three principal components (PCs) were determined for each sowing date. The cumulative percentages of variation for three PCs at the first to fourth sowing dates were 0.97, 0.96, 0.89 and 0.95, respectively. At the first sowing date, the first principal component (PC1) had high positive and negative PC loading values for the studied traits such as days to flowering, days to the end of flowering, duration of flowering, pods per plant and harvest index. Therefore, there was high variation in these traits among the genotypes. PC2 of the first sowing date had also high PC loadings for pods on the main raceme, seeds per pod, 1000-seed weight, biological and seed yields, therefore the correlation of these traits with this PC will be high. In PC3 of the first sowing date, height, pods on the main raceme and pods per plant had the high value of PC loadings. Based on stepwise regression analysis, seeds per pod at the first and second sowing dates and days to flowering and pods per plant at the third and fourth sowing dates had an important role for improving seed yield.

1977 ◽  
Vol 57 (2) ◽  
pp. 317-321 ◽  
Author(s):  
G. H. GUBBELS

Two buckwheat (Fagopyrum esculentum Moench.) cultivars, Tokyo and Tempest, were grown in 1971, 1972 and 1973 at 8.5, 17, 34 and 68 kg/ha sowing rates and at early, mid- and late June sowing dates. Tempest lodged more than Tokyo, particularly in 1971. Yield generally declined with each delay in sowing. In 1971, yield increased with each increase in sowing rate, while in 1972 there was no difference due to rate. In 1973, yield increased to the third rate and levelled out to the fourth. Therefore, a sowing rate of over 34 kg/ha may be required to assure good yields each year. Seed weight tended to decrease with delay in sowing but was not affected by sowing rate.


Author(s):  
Magdalena Borowska ◽  
Janusz Prusiński

The article presents the effect of three sowing dates on the growth, development and yielding of four soybean cultivars of different earliness and under different temperature and precipitation conditions across the years. The seed yield from early sowing significantly correlated with the total precipitation in June and July, and at later dates, also with the total precipitation in August. The significantly highest soybean yields were collected from the sowing at a turn of April and May, and the highest seed and protein yield, as well as protein content in seed, were recorded for the mid-early Merlin cultivar. Neither the number and the seed weight per pod nor the 1 000-seed weight significantly depended on the sowing date. Over years, a significant, almost linear decrease in the plant height and the first pod setting height, the weight of nodules, the protein yield and the LAI (leaf area index) value was observed. High significant correlations were found between the seed yield and the plant height and the first pod setting height, as well as between the seed number and the seed weight per pod and the 1 000-seed weight as well as between the plant height and the first pod setting height.  


2020 ◽  
Vol 22 (2) ◽  
pp. 83-89
Author(s):  
ATMM Alam ◽  
MM Haque

Feld experiments were conducted at four locations of Bangladesh (Manikgonj, Cumilla, Dinajpur and Joshore) to optimize sowing date for higher seed yield of jute in late sown condition. The experimental variables constituted with three genotypes (O-72, O-3820 and Acc.4311) and three sowing dates (31 July, 15 August and 30 August).Each experiment was laid out in a randomized complete block design with three replications. The treatment combinations were assigned randomly and afresh randomization was followed in each replication. Results showed that the genotype Acc.4311, O-72 and O- 3820 produced maximum number of branches (5.40, 4.90 and 4.40, respectively) plant-1 on 15 August sowing at Manikgonj. The genotype Acc.4311 produced higher number of pods plant-1 than other two genotypes (O-72 and O-3820) in all sowing dates andat all the locations. The highest number of seedspod-1 (220.80) was found from the genotype Acc.4311grown at Manikgonj which was statistically similar (196.90) with that of the same genotype sown on the same date at Joshore. The highest thousand seed weight (2.478 g) was recorded from the seeds of genotype Acc.4311 sown on 15 August at Manikgonj followed by same genotype at Joshore.Finally, the genotype Acc.4311 sown on 15 August produced the highest seed yield (2.478 t ha-1) at Manikgonjwhich was significantly higher than those of sown on 31 July and 30 August at the same location. As the genotype Acc.4311 was found outstanding sown on 15 August over locations, this genotype may be considered promising for higher seed yield of olitorius jute in late season. Bangladesh Agron. J. 2019, 22(2): 83-89


2020 ◽  
Vol 23 (1) ◽  
pp. 67-73
Author(s):  
PK Biswas ◽  
ZA Tanni

The experiment was conducted at Sher-e-Bangla Agricultural University, Dhaka with the financial support of SAURES (Sher-e-Bangla Agricultural University Research System) to study the possibility of growing quinoa in Bangladesh with different sowing dates having two cultivars. The experiment comprised of two factors; Factor A: Cultivar (2) viz., Titicaca (C1) and Vikinga (C2) and Factor B: Sowing date (5) viz. November -10 (S1), December -10 (S2), January -10 (S3), February -10 (S4) and March -10(S5). The experiment was laid out in split-plot design with three replications. Results revealed that different growth parameters, yield attributes and yield were significantly varied with different sowing dates. At harvest, the tallest plant height (63.75 cm), highest seed yield (0.77 t ha-1) and straw yield (0.89 t ha-1) was found from Titicaca but the higher number of branches plant-1 (17.71) from Vikinga. The tallest plant height (62.54 cm), highest branch number plant-1 (22.82), longest inflorescence (29.62 cm), highest 1000-seed weight (2.56 g), seed yield (1.09 t ha-1), straw yield (1.25 t ha-1) and harvest index (46.58%) was exhibited by November -10 sowing. The interaction effect of Titicaca sown in November -10 (C1S1) resulted the highest plant height at harvest (72.83 cm), branches plant-1 (25.20), 1000-seed weight (2.58 g), seed yield (1.16 t ha-1) and straw yield (1.33 t ha-1) but the highest inflorescence length (31.46 cm) and harvest index (47.02%) from C2S2 (Vikinga sown in December – 10). From the above results it can be concluded that quinoa – as a new crop is suitable to cultivate in Rabi season of Bangladesh with a complete agronomic management package. Bangladesh Agron. J. 2020, 23(1): 67-73


2011 ◽  
Vol 62 (1) ◽  
pp. 1 ◽  
Author(s):  
R. J. Lawn ◽  
A. T. James

The purpose of this paper and its companion1 is to describe how, in eastern Australia, soybean improvement, in terms of both breeding and agronomy, has been informed and influenced over the past four decades by physiological understanding of the environmental control of phenology. This first paper describes how initial attempts to grow soybean in eastern Australia, using varieties and production practices from the southern USA, met with limited success due to large variety × environment interaction effects on seed yield. In particular, there were large variety × location, variety × sowing date, and variety × sowing date × density effects. These various interaction effects were ultimately explained in terms of the effects of photo-thermal environment on the phenology of different varieties, and the consequences for radiation interception, dry matter production, harvest index, and seed yield. This knowledge enabled the formulation of agronomic practices to optimise sowing date and planting arrangement to suit particular varieties, and underpinned the establishment of commercial production in south-eastern Queensland in the early 1970s. It also influenced the establishment and operation over the next three decades of several separate breeding programs, each targeting phenological adaptation to specific latitudinal regions of eastern Australia. This paper also describes how physiological developments internationally, particularly the discovery of the long juvenile trait and to a lesser extent the semi-dwarf ideotype, subsequently enabled an approach to be conceived for broadening the phenological adaptation of soybeans across latitudes and sowing dates. The application of this approach, and its outcomes in terms of varietal improvement, agronomic management, and the structure of the breeding program, are described in the companion paper.


Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 161
Author(s):  
Alberto A. Chassaigne-Ricciulli ◽  
Leopoldo E. Mendoza-Onofre ◽  
Leobigildo Córdova-Téllez ◽  
Aquiles Carballo-Carballo ◽  
Félix M. San Vicente-García ◽  
...  

Genotype, environmental temperature, and agronomic management of parents influence seed yield in three-way cross hybrid maize seed production. The objective of this research was to generate information on the seed production of six three-way cross hybrids and their progenitors, adapted to tropical lowlands. Data on days to—and duration of—flowering, distance to spike and stigmas, and seed yield of five female single crosses and five male inbred lines were recorded for different combinations of four planting densities and four sowing dates in Mexico. The effect of planting density was not significant. The male inbred line T10 was the earliest and highest seed yield and T31 the latest, occupying second place in yield. The single crosses T32/T10 and T13/T14 were the earliest and had the highest effective seed yield. At the earliest sowing date, the females were later in their flowering, accumulated fewer growing degree days (GDD), and obtained higher yields since the grain-filling period coincided with hot days and cool nights. To achieve greater floral synchronization and therefore greater production of hybrid seed, differential planting dates for parents are recommended based on information from the accumulated GDD of each parent. The three-way cross hybrids were classified according to the expected seed yield of the females and the complexity in the synchronization of flowering of their parents.


2012 ◽  
pp. 89-93
Author(s):  
Tamás Árendás ◽  
Zoltán Berzsenyi ◽  
Péter Bónis

The effect of crop production factors on the grain yield was analysed on the basis of three-factorial experiments laid out in a split-split-plot design. In the case of maize the studies were made as part of a long-term experiment set up in 1980 on chernozem soil with forest residues, well supplied with N and very well with PK. The effects of five N levels in the main plots and four sowing dates in the subplots were compared in terms of the performance of four medium early hybrids (FAO 200). In the technological adaptation experiments carried out with durum wheat, the N supplies were moderate (2010) or good (2011), while the P and K supplies were good or very good in both years. Six N top-dressing treatments were applied in the main plots and five plant protection treatments in the subplots to test the responses of three varieties. The results were evaluated using analysis of variance, while correlations between the variables were detected using regression analysis.The effect of the tested factors on the grain yield was significant in the three-factorial maize experiment despite the annual fluctuations, reflected in extremely variable environmental means. During the given period the effect of N fertilisation surpassed that of the sowing date and the genotype. Regression analysis on the N responses for various sowing dates showed that maize sown in the middle 10 days of April gave the highest yield, but the N rates required to achieve maximum values declined as sowing was delayed. In the very wet year, the yield of durum wheat was influenced to the greatest extent by the plant protection treatments, while N supplies and the choice of variety were of approximately the same importance.  In the favourable year the yielding ability was determined by topdressing and the importance of plant protection dropped to half,  while no  significant difference could be detected between the tested varieties. According to the results of regression analysis, the positive effect of plant protection could not be substituted by an increase in the N rate in either year. The achievement of higher yields was only possible by a joint intensification of plant protection and N fertilisation. Nevertheless, the use of more efficient chemicals led to a slightly, though not significantly, higher yield, with a lower N requirement. 


Author(s):  
R. Borah ◽  
N. Baruah ◽  
P. K. Sarma ◽  
R. Borah ◽  
A. Sonowal ◽  
...  

A field experiment was conducted during rabi season of 2018-19 and 2019-20 in Dryland experimental field belong to soil order Inceptisols, Biswanath college of Agriculture, Assam Agricultural University, Biswanath chariali, Assam to study the ‘‘Yield and yield attributing parameters of toria (Brassica campestries) under real time rainfall situation in an Inceptisols of Assam, India’’ under AICRPDA, NICRA. The treatments consisting of 4 different dates of sowing i.e. S1-41th SMW, S2-44th SMW, S3-46th SMW, and S4- 48th SMW, & three variety i.e. V1-JT-90-1(Jeuti), V2-Yellow sarson (Benoy) and V3- TS-38. Growth, yield and yield attributing characters of toria varieties were influenced by different dates of sowing. S1 registered higher plant height (43.2 cm, 92.9 cm and 106.6 cm & 40.2 cm, 89.8 cm and 101.5 cm) and number of branch (3.8, 5.3 and 7.2 & 3.4, 5.1 and 6.9) at 30 DAS, 45 DAS and 60 DAS, respectively, during 2018-19 and 2019-20. Yield attributing characters like number of siliqua, number of seed per siliqua, 1000 seed weight (g) were gradually decreased with advancement of sowing dates. Among the three varieties V1 (Jeuti) recorded highest seed yield (8.9 q ha-1 and 8.1 q ha-1) and stover yield (23.4 q ha-1 and 22.2 q ha-1) in 2018-19 and 2019-20, respectively. Highest HI (28.5% and 25.8%) was recorded in S1 and lowest was recorded in S4 (20.7% and 14.6%).


1959 ◽  
Vol 39 (3) ◽  
pp. 355-363 ◽  
Author(s):  
R. S. Fulkerson

The effects of six seeding rates and five row spacings on seed yield, seed quality and the yield components—number of fertile culms per square foot, number of seeds per culm and seed weight were studied in orchard grass.Row width had a marked effect on seed yield each year. Rate of seeding affected seed yield to a lesser extent and a row width × seeding rate interaction did occur. Seeding rates and row width caused small relatively unimportant differences in seedling establishment and early seedling vigour only in the third harvest year. Considering seed yield, seed quality and the ease of weed control, the best treatment combination appeared to be a seeding rate in the area of [Formula: see text] in 14-in. rows for stands to produce for 2 or 3 years.Seed yield was positively and closely correlated with the number of fertile culms in the first 2 crop years but a negative relationship was found in the third crop year. Seed weight was negatively correlated with seed yield. The number of seeds per panicle was closely associated with yield in the third crop year and negatively correlated with seed weight and culm numbers.


2019 ◽  
Vol 113 (1) ◽  
pp. 51 ◽  
Author(s):  
Paolo CASINI

<p>Research on the introduction of quinoa in Italy is currently lacking. The present research was aimed at identifying the correct sowing period. Field experiment was consucted in Cesa, Tuscany, in 2017. Two new breeding lines coded as DISPAA-Q42 and DISPAA-Q47-CB were utilized. Three sowing dates (SD) were implemented: February 23; March 17 and April 27. Results showed that the most successful SD was February 23. A significant decrease in both seed yield and a delay in phenological phases, relating to plant maturation and flowering was associated with the sequential delay in SD in both lines. Results also showed a significant effect of lines on yield, true-leaf stage development, flower development and maturity. Only DISPAA-Q42 was considered suitable for cultivation in the Tuscan environment. DISPAA-Q47-CB was the more susceptible line, due to the sequential delay in SD and delayed plant maturation. No effect between lines was evident for protein and saponin content. The present study clearly shows the potential for the successful cultivation of quinoa in Central Italy, and highlights the necessity of taking into consideration both breeding lines and SD in order to accomplish this goal.</p>


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